The Digital Rebel XSi is Canon's latest contestant in the consumer DSLR market. It's aimed at the new DSLR user, or someone upgrading from an earlier Digital Rebel camera. Compared to the Canon EOS 40D, it's smaller, lighter and cheaper, though it lacks a few features of the EOS 40D such as an ISO 3200 setting, a read QCD, a top mounted LCD, as well as having a smaller image buffer and slower maximum frame rate. However it does have more pixels (12MP vs. 10MP) and some LiveView features not present on the EOS 40D.
More reading on the Digital Rebel XSi...
So how does it all look? Well, my first impressions are quite favorable. The new Digital Rebel XSi has a nice large LCD (3"). It's very legible, though in bright sunlight like all transmission type LCDs it gets hard to read. That's where a top mounted reflection type LCD shines. The brighter the light, the more readable it gets! Most entry level DSLRs these days go without a top mounted LCD, presumably for both reasons of space and cost.
If the LCD is hard to read in direct bright sunlight, the viewfinder does readout shutter speed, aperture, exposure compensation setting and, for the first time on a Digital Rebel DSLR, the ISO speed setting. The camera controls should be pretty familiar to any Canon EOS DSLR user. Most of the important functions (ISO, white balance, AF mode, Metering mode, Shooting mode etc.) have dedicated buttons and the top mounted dial allows selection between Aperture Priority, Shutter Priority, Intelligent Program, Manual and pre-programmed exposure control. The dedicated ISO button is another new feature for the Digital Rebel series.
Another change from earlier Digital Rebels is the use of SD(HC) memory cards. All other Canon DSLRs use CF cards (though msny series 1D bodies can use both SD and CF cards). Today it really doesn't much matter whether you use SD(HC) or CF cards. Prices are fairly similar and both are available in high capacity versions (8GB cards aren't hard to find and 16GB and 32GB versions are available). While the fastest CF cards are faster than the fastest SD cards, that's not going to matter to Digital Rebel owners since the camera itself will limit the recording speed. The only issue is one of compatibility with other cameras so you don't need to carry two types of card. Most P&S digicams use SD cards, while most other Canon EOS DSLRs use CF cards.
The Rebel XSi also uses a different Li-ion battery then any other EOS DSLR, the LP-E5. It offers more capacity than the batteries used in previous Digital Rebel bodies, but it only fits the XSi.
Like previous Digital Rebels, the XSi doesn't have the rear QCD (quick control dial) found on the EOS 40D, which means for a few things (like setting exposure compensation), you have to press a button and use the main control dial rather than just spinning the rear QCD with your thumb. Slightly slower and more complex than on the 40D, but I suppose equally effective once you've memorized the procedure.
A quick test at ISO 1600 did seem to show that the Rebel XSi is slightly noisier then the EOS 40D, which wouldn't be unexpected as the higher pixel count of the XSi means the use of smaller pixels, and, all else being equal, smaller pixels means higher noise. I haven't looked at this in detail and differences could be due to different noise reduction and/or sharpening algorithms in the XSi and 40D
The above 100% crops from a color test chart show slightly higher noise in the Rebel XSi image. Note that these are "straight out of the camera JPEGs". Both cameras had high ISO noise reduction turned off. As you can see color rendition is almost identical too.
The EF-S 18-55/3.5-5.6IS and EF-S 55-250/4-5.6IS lenses are Canon's answer to Sony, Pentax and Olympus entry level DSLRs with sensor-shift stabilization built into the body. Body based stabilization offers image stabilization with ANY lens mounted on the camera, while Nikon and Canon are staying with a lens based system which requires a lens with stabilized optics be used. To lower costs Canon have used a different electro-mechanical stabilization system in these two lenses which is simpler and cheaper than previous system, though Canon claim that there is no loss in performance (up to 4 stops of stabilization is possible according to Canon).
The EF-S 18-55/3.5-5.6IS USM is offered with the Digital Rebel XSi as a kit and adds only $100 to the price of the camera body alone. This is a pretty good deal since the lens will cost you around $175 if you buy it without the XSi body. As I will comment later, it's not a bad lens at all.
Though the 18-55is and 55-250is are relatively low cost lenses (very low cost in terms of Canon IS lenses), with plastic barrels and lens mounts, Canon have put some effort into maximizing optical quality. An aspheric element is used in the 18-55 and a UD element is used in the 55-250. Both lenses also use curved aperture blades to make the lens iris closer to a circle when stopped down for better defocus quality.
Neither lens has a distance scale or DOF markings as it common with entry level lenses. The 18-55 utilizes a knurled ring on the end of the barrel for manual focusing, but the 55-250 has a separate focusing ring. The front element of both lenses rotates during focusing (but not during zooming). Though neither lens uses a USM focusing motor, focusing is fairly quite and fairly fast, but it's not silent like lenses with a USM ring motor are. In a quite room you would hear it, but outdoors in normal operation is quiet enough not to be noticeable.
In use both lenses seemed very resistant to flare, indicating the use of very effective anti-reflection coatings. Sharpness was generally good and chromatic aberration was well controlled.
On the downside, there was visible barrel distortion at 18mm from the 18-55IS and there was visible vignetting from the 55-250IS when shot wide open at longer focal lengths (150mm and up). Neither defect is very serious, both can be digitally corrected and both would be expected from lenses in this price range.
I've worked with the Digital Rebel XSi and the 18-55IS and 55-250IS for a few days at this point, taking around 250 shots. Overall I have a favorable impression of both the camera and lenses and together I think they would make a very capable kit for someone just getting into DSLR photography. The XSi seems simple enough for anyone to use at the default settings, but offers a large degree of manual control for those who want to move beyond the basics. Exposure and autofocus seem accurate, color rendition is good (similar to the EOS 40D) and noise is well controlled. You could think of the XSi as pretty much an "EOS 40D Lite", with similar performance and handling, but with a few less features. The EF-S 18-55is and 55-250is lenses, while probably not the best optics in the world, are actually quite good and the IS system seems to be effective. If I was buying the camera, I'd definitely get the kit with the 18-55IS included. At this point I'd say the XSi is a recommended camera. If it has any significant faults or problems, I haven't found them yet!
Of course many potential buyers of the Digital Rebel XSi might wonder if they should spend $250-300 more for the Canon EOS 40D. The 40D is more solidly built and has a few more professional features (ISO 3200, PC socket for flash, 2nd LCD display, QCD, larger buffer, faster frame rate etc.) as described in my XTi vs. XSi vs. EOS 40D article.
Another option for those who don't already have an investment in Canon lenses might be the Pentax K200D. It has sensor-shift stabilization built into the body which means all lenses become stabilized and it's available in a kit with an 18-55/3.5-5.6 zoom for around $570
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